control the display of prices fractional part

I want to display price like that $9.99 (if price = $9.99)
and like that $10 (if price = $10.00)
i.e. if price has fractional part, then display fractional part
if not, then doesn't display fractional part

There is no option for that.
You would have to edit all the views where prices are displayed and change the display code to strip the cents display if it's 00.
For example, in the "listing_price" view file that you can edit via the menu Display->Views, you have these sort of lines:
echo $this->currencyHelper->format($price->price_value_with_tax,$price->price_currency_id);

and you should change them to:
echo str_replace('.00','',$this->currencyHelper->format($price->price_value_with_tax,$price->price_currency_id));